Magnetic and transport properties of monocrystalline Fe3O4

A monocrystal of Fe3O4 is characterized by resistance, magnetoresistance and magnetic measurements in a temperature range from 4.2 K to 350 K and magnetic field-cycling from -9 T to 9 T. The resistance measurements revealed a metal-insulator Verwey transition (VT) at T-v = 123.76 K with activation energy E = 92.5 meV at T > T-v and temperature-substitute for the activation energy below the VT, T-0 = E/k(B) approximate to 3800 K within 70 K - HO K. The magnetotransport results independently verified the VT at 123.70 K, with discontinuous change in the magnetic moment DeltaM approximate to 0.21 mu(B) and resistance hysteresis, dependent on the magnetic field in a narrow temperature range of 0.4(0) around the T-v. The magnetic characterization established self consistently T-v as approximate to 123.67 K, the jump in the magnetization at the VT approximate to 0.25 mu(B) and confirmed, that the magnetocrystalline anisotropy is the main microscopic mechanism responsible for the magnetization of the monocrystal (88%) with additional natural and imposed defects contributing as 12%. (C) Central European Science Journals. All rights reserved.